While Foucault would have us cut off the king’s head in political theory, he wouldn’t have us do away with cutting as such – the process of making divisions is the content of Foucault’s contribution to political theory.

Not sure if he means the only contribution, the main contribution, or one of his contributions (couldn’t we as easily say “governmentality” and “biopolitics” since the latter was interesting enough for Agamben to steal it and from there has made its way into the disciplines?).

Oh well. Craig is right that it was a part of Foucault’s analysis. Here is the key quote:

The subject is either divided inside himself or divided from others. This process objectivizes him. Examples are the mad and the sane, the sick and the healthy, the criminals and the “good boys” (Foucault “The Subject and Power”: 208).

These are the famous “dividing practices” that divide the normal from the abnormal. Elsewhere he describes how we take an essentially continuous variable (“life” say) and cut (coupure) into it to create the races and racism (discussion on biopower and racism, Society Must be Defended, last lecture).
So, yes. And for me it feeds into things in a lot of interesting and useful ways.